package LanQiaoCompetition.LanQiaoCompetition2;

import java.util.Scanner;

public class Basic_22 {

    static String result = "";
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int n = scanner.nextInt();
        for(int i=0;i<n;i++){
            function(i);
        }
        System.out.println(result);
    }

    public static void function(int n){
        result = result + (char)(65+n) +result;
    }
}
